There has been proposed a related art image forming apparatus capable of forming images on both sides of a sheet. For example, JP-A-2002-104694 (refer to FIG. 1, for example) discloses an example of the related art image forming apparatus, in which the sheet is first conveyed in a reverse feeding path by reverse turning of a discharge roller, passes through the reverse feeding path, and is conveyed again into a feeding path while reversing a conveyance direction of the sheet at a forward (i.e., upstream side in the conveyance direction of the sheet) of a registration roller provided immediately before a contacting position (i.e., an image forming position) of a photosensitive drum and a transfer roller. The sheet passes through the registration roller again and is conveyed to the image forming position.